'''
 str() int() list() set() tuple() dict() float()
 str 可以转 int list set tuple
 int list set tuple dict float 可以转 str
 list 可以转 set tuple dict(需要[(key,value)]成对出现)
 set tuple dict 可以转 list
 tuple 可以转 list set
'''
s1 = '8'
print(int(s1))
s2 = 'abc'
print(list(s2))
print(tuple(s2))
print(set(s2))

tuple1 = (1,2,3)
print(list(tuple1))
print(set(tuple1))

list1 = [1,2,3,4]
print(tuple(list1))
print(set(list1))

dict1 = {1:'a',2:'b'}
print(list(dict1)) #将字典中的key转换放在列表中


